The incident occurred after Harrison tackled running back Clyde Edwards-Helaire along the Kansas City sideline on the Chiefs' opening drive. As Harrison got up, he bumped into Chiefs center Creed Humphrey and stepped on Edwards-Helaire. After Kansas City running backs assistant Greg Lewis shoved Harrison away, Harrison retaliated by pushing him in the neck.
Officials initially flagged the Kansas City bench with unsportsmanlike conduct. But after reconvening, they reversed the penalty, flagging and ejecting Harrison.
Browns coach Kevin Stefanski said after the game that he didn't see the incident and wanted to do so before commenting.
Said Chiefs coach Andy Reid: "He was on the chest of our player. [Lewis] was trying to get him off, and he didn't want to get off. [Lewis] kind of lifted him just a little bit and he got hit. [Lewis] was there to help get that fella who was leaning on our guy. That's why there was a penalty, right? The officials fixed it, which I thought was important. You don't do that on our sideline. You don't do that to our guys, bottom line."
The Browns also lost left tackle Jedrick Wills Jr., who was carted off the field and ruled out with an ankle injury.
ESPN's Adam Teicher contributed to this report.